Real-time Operating System Research Articles

Real-time processing system of a two-color CO2 laser interferometer for density feedback control in JT-60SA.

A real-time processing system for the two-color CO2 laser interferometer on the JT-60SA has been developed for density feedback control. The system has a novel feature that can detect fringe jumps due to off-normal events, such as loss detection due to displacement of the beam axis and changes in the laser wavelengths. Because a phase change due to the JT-60SA plasma is smaller than π/2, corresponding to the line-integral electron density NL of ∼6×1019 m-2 in a short interval of 500ns, the threshold of the fringe jump detection is decided to be π/2. Hence, off-normal events can be detected from a fringe jump, leading to the abort of the real-time feedback control. In the density feedback control of the JT-60SA plasma, the system is employed as a density monitor, with NL being successfully controlled at 16.8% ± 6.6% lower than the reference.

AI Revolution in Exit Polls: Enhancing Accuracy, Efficiency, and Inclusivity

Exit polls have long been integral to understanding electoral dynamics, offering insights into voter behavior and preferences. Traditional exit poll methodologies, involving manual data collection and in-person interviews, face significant challenges in accuracy, sample size, and inclusivity. This paper explores the transformative impact of Artificial Intelligence (AI) on the exit polling process. By leveraging neural networks for enhanced sampling, employing automated Voice-AI for data collection, and utilizing Natural Language Processing (NLP) for real-time data analysis, AI significantly improves the efficiency, accuracy, and inclusivity of exit polls. The paper discusses the technical aspects of implementing AI-driven exit polls, including the architecture of neural networks, real-time data processing systems, and machine learning models for prediction. Additionally, it addresses the advantages of AI, such as cost-effectiveness and reduced human biases, while acknowledging challenges like algorithmic bias, privacy concerns, and the complexities of accurately interpreting voter behavior. As AI continues to evolve, it promises to further enhance the reliability and comprehensiveness of exit polls, providing valuable tools for understanding public opinion in democratic processes

MOBILE ROBOT TRACKING SYSTEM BASED ON MACHINE VISION AND LASER RADAR

The proposed solution addresses the issue of insufficient real-time performance and accuracy in mobile robot path tracking by introducing a system that combines machine vision and laser radar. In this study, the Broadcom BCM2711 microcontroller chip is connected to the RS232 communication interface for transmitting information to the ARM embedded processor. Users can access position distance, direction, and other robot-related data through the man-machine interface's LCD display in a Windows operating system environment. By initiating an adaptive position tracking algorithm program identified by the robot within the position tracking unit, mobile position tracking of the robot is achieved. Experimental results demonstrate significant improvements in both real-time performance and accuracy of this mobile robot tracking system.

Research on the Application of Embedded Real-time Software in Computer Software Design

With the continuous development of computer technology, embedded real-time software is also developing and improving. In the design of computer software, embedded real-time software is the core part, and its reasonable application can effectively improve the function and performance of computer software and ensure its stable and reliable operation. At the same time, embedded real-time software can effectively realize the real-time operation of computers and bring convenience to people's daily life and work. This paper deeply studies the application of embedded real-time software in computer software design. The key technologies and methods such as real-time operating system, real-time task scheduling algorithm, embedded software design mode and embedded software testing and verification method are discussed in detail. Combined with specific cases, the application practice of embedded real-time software in computer software design is analyzed, including real-time requirements analysis, performance optimization, resource management and application in specific fields. This paper analyzes the specific application of embedded real-time software in computer software design, and provides some reference for related workers.

The Influence of Temporal Disturbances in EKF Calculations on the Achieved Parameters of Flight Control and Stabilization of UAVs.

This article investigates the causes of occasional flight instability observed in Unmanned Aerial Vehicles (UAVs). The issue manifests as unexpected oscillations that can lead to emergency landings. The analysis focuses on delays in the Extended Kalman Filter (EKF) algorithm used to estimate the drone's attitude, position, and velocity. These delays disrupt the flight stabilization process. The research identifies two potential causes for the delays. First cause is magnetic field distrurbances created by UAV motors and external magnetic fields (e.g., power lines) that can interfere with magnetometer readings, leading to extended EKF calculations. Second cause is EKF fusion step implementation of the PX4-ECL library combining magnetometer data with other sensor measurements, which can become computionally expensive, especially when dealing with inconsistent magnetic field readings. This can significantly increase EKF processing time. The authors propose a solution of moving the magnetic field estimation calculations to a separate, lower-priority thread. This would prevent them from blocking the main EKF loop and causing delays. The implemented monitoring techniques allow for continuous observation of the real-time operating system's behavior. Since addressing the identified issues, no significant problems have been encountered during flights. However, ongoing monitoring is crucial due to the infrequent and unpredictable nature of the disturbances.

Distributed real-time control architecture for electrohydraulic humanoid robots

PurposeThis paper aims to develop an adaptable control architecture for electrohydraulic humanoid robots (HYDROïD) that emulate the functionality of the human nervous system. The developed control architecture overcomes the limitations of classical centralized and decentralized systems by distributing intelligence across controllers.Design/methodology/approachThe proposed solution is a distributed real-time control architecture with robot operating system (ROS). The joint controllers have the intelligence to make decisions, dominate their actuators and publish their state. The real-time capabilities are ensured in the master controller by using a Preempt-RT kernel beside open robot control software middleware to operate the real-time tasks and in the customized joint controllers by free real-time operating systems firmware. Systems can be either centralized, where all components are connected to a central unit or decentralized, where distributed units act as interfaces between the I/Os and the master controller when the master controller is without the ability to make decisions.FindingsThe proposed architecture establishes a versatile and adaptive control framework. It features a centralized hardware topology with a master PC and distributed joint controllers, while the software architecture adapts based on the task. It operates in a distributed manner for precise, force-independent motions and in a decentralized manner for tasks requiring compliance and force control. This design enables the examination of the sensorimotor loop at both low-level joint controllers and the high-level master controller.Originality/valueIt developed a control architecture emulating the functionality of the human nervous system. The experimental validations were performed on the HYDROïD. The results demonstrated 50% advancements in the update rate compared to other humanoids and 30% in the latency of the master processor and the control tasks.

On [formula omitted]-performance of weakly-hard real-time control systems

This paper considers control systems with failures in the feedback channel, that occasionally lead to loss of the control input signal. A useful approach for modeling such failures is to consider window-based constraints on possible loss sequences, for example that at least r control attempts in every window of s are successful. A powerful framework to model such constraints are weakly-hard real-time constraints. Various approaches for stability analysis and the synthesis of stabilizing controllers for such systems have been presented in the past. However, existing results are mostly limited to asymptotic stability and rarely consider performance measures such as the resulting ℓ2-gain. To address this problem, we adapt a switched system description where the switching sequence is constrained by a graph that captures the loss information. We present an approach for ℓ2-performance analysis involving linear matrix inequalities (LMI). Further, leveraging a system lifting method, we propose an LMI-based approach for synthesizing state-feedback controllers with guaranteed ℓ2-performance. The results are illustrated by a numerical example.

Traffic Sign Recognition Using Deep Learning

Abstract: Traffic sign recognition is a crucial component in advanced driver assistance systems and autonomous vehicles, enhancing road safety and overall transportation efficiency. Deep learning, specifically convolutional neural networks (CNNs), has emerged as a powerful tool for image based recognition tasks. The proposed deep learning-based traffic sign recognition system exhibits promising results, providing a foundation for the development of intelligent transportation systems. The trained model demonstrates remarkable accuracy in recognizing a wide range of traffic signs under different scenarios, including challenging lighting conditions and occlusions. The system's real-time performance is evaluated on both simulated and actual road scenarios, showcasing its feasibility for deployment in practical driving environments. The integration of such technology into vehicles holds great potential for enhancing road safety, reducing accidents, and contributing to the evolution of autonomous driving technology.

Rancang Bangun Sistem Transfer Liquid Berbasis Arduino Uno Menggunakan Sensor YF-S401

This article discusses the design of a liquid transfer system using a YF-S401 flow sensor and the evaluation of various calibration factors to create a reliable system. The research methods included water flow measurement, system component selection, system design, and workflow. The research results showed that a calibration factor of 50 was the optimal choice, showing good liquid transfer precision at a scale of 100 ml. However, testing at a scale of 200 ml and 300 ml showed suboptimal performance, especially in maintaining liquid transfer precision. Further development recommended in the selection of more reliable components, the improvement of the Arduino Uno program, and the implementation of technologies such as real time operating system (RTOS) to improve the accuracy of the liquid transfer system at larger scales. Overall, this research provides important insights for the development of automatic liquid transfer systems with a focus on precision in various measurement scales. Keywords—Liquid transfer system, Flow sensor, Calibration factor, Water flow measurement, Arduino Uno

Development of a dynamic traffic microsimulator for on-demand transit operations within an integrated modelling system

ABSTRACT This study develops an intelligent dynamic agent-based microsimulation (iDAMS) module for on-demand transit (ODT) operations within an integrated transport, land-use and energy (iTLE) model. A real-time optimization component within the iDAMS is formulated by the utilization of travelling salesman problem and simulated annealing metaheuristics that perform dynamic passenger-vehicle assignment. It simulates ODT operations for meeting the 24-hour auto-trip demand of Halifax, Canada, to compare the performance of the proposed system with personal cars (PCs). The optimization objectives are to determine the optimal fleet size and seat capacity that satisfies maximum trip requests while minimizing waiting time, travel time and vehicle kilometres travelled (VKT). Simulation results indicate that the ODT system can deliver service similar to PCs in Halifax while decreasing cost and emissions (13% reduction in VKT). The tools developed in this research will provide transit planners ability to conduct ODT scenario simulation and test system performance in real time.

Research on the Positioning Method of Steel Belt Anchor Holes Applied in Coal Mine Underground

In order to improve the automation and safety of underground steel belt support in coal mines, a method for the intelligent identification and positioning of steel belt anchor holes in roadway support using inductive sensors is proposed. Using STM32F407ZGT6 as the main control chip, tasks such as data acquisition and processing, motor motion control, etc., are assigned based on the real-time operating system FreeRTOS. Using the XY mobile platform equipped with inductive sensors to detect steel belts, The collected data includes coordinate values and voltage values. Adaptive threshold generation and correction strategies are used for threshold segmentation and extraction of anchor hole boundary points. The principle of Hough circle transformation is used to fit the extracted boundary points into circles. The results show that this method can perform anchor hole positioning with a positioning error of within 5 mm, meeting the design requirements.

Optimization research of handwritten digit recognition algorithm based on hardware neural networks

In the modern era of digitization, the widespread application of handwritten numerical data has led to an exponential increase in data volume, necessitating efficient real-time recognition and processing systems. This project is grounded in the foundational structure of neural networks, with a specific focus on integrating these networks into hardware through Very-Large-Scale Integration (VLSI). The primary objective is to achieve faster processing speeds, lower power consumption, and real-time operations. The central emphasis of this study is the design and implementation of a hardware neural network system tailored specifically for handwritten digit recognition. Drawing from neural network theory, we explore the construction of a hardware-based handwritten digit classifier. The fundamental model employed is the single-layer perceptron neuron model. Upon receiving 28x28 pixel grayscale images, the image classifier utilizes pre-trained weights, activation functions, and a maximum selector to compare and output recognition results for numerical digits. The concrete implementation is realized using the Verilog hardware description language, coupled with algorithm optimization strategies to enhance performance and efficiency. This research endeavor aims to provide an effective hardware solution for real-time handwritten digit recognition in the digital age.

A Novel Approach to Managing System-on-Chip Sub-Blocks Using a 16-Bit Real-Time Operating System

Embedded computers are ubiquitous in products across various industries, including the automotive and medical industries, and in consumer goods such as appliances and entertainment devices. These specialized computing systems utilize Systems on Chips (SoCs), devices that are made up of one or more main microprocessor cores. SoCs are augmented with sub-blocks that perform dedicated tasks to support the system. Sub-blocks contain custom logic or small-footprint microprocessors, depending upon their complexity, and perform support functions such as clock generation, device testing, phase-locked loop synchronization and peripheral management for interfaces such as a Universal Serial Bus (USB) or Serial Peripheral Interface (SPI). SoC designers have traditionally obtained sub-blocks from commercial vendors. While these sub-blocks have well-defined interfaces, their internal implementations are opaque. Without visibility of the specifics of the implementation, SoC designers are limited to the degree to which they can optimize these off-the-shelf sub-blocks. The result is that power and area constraints are dictated by the design of a third-party vendor. This work introduces a novel idea: using an open-source, small, multitasking, real-time operating system inside an SoC sub-block to manage multiple processes, thereby conserving code space. This OS is TurbOS, a new operating system whose primary goal is to provide the highest performance using the least amount of space. It is written in the assembly language of a new pipelined 16-bit microprocessor developed at the University of Florida, the Turbo9. TurbOS is derived from and incorporates the design benefits of an existing operating system called NitrOS-9, and reduces the code size from its progenitor by nearly 20%. Furthermore, it is over 80% smaller than the popular FreeRTOS operating system. TurbOS delivers a rich feature set for managing memory and process resources that are useful in SoC sub-block applications in an extremely small footprint of only 3 kilobytes.

Research on electronic optical monitoring technology and system design for vacuum electron beam welding process

Electron beam welding technology is increasingly used in industrial manufacturing due to its high power density and the purity of welded joints. In vacuum environments, traditional optical and machine vision monitoring methods are susceptible to contamination by metal vapors, which hinders the monitoring effect. Due to the limitations of optical monitoring methods, electronic optical imaging technology is a new alternative monitoring method that has been introduced into the electron beam processing in recent years, but the complexity of the industrial electron beam welding environment makes it relatively less studied in the field of electron beam welding. In this study, a YAG scintillator detector is proposed to collect the backscattered electron information generated by the interaction of electrons with the sample, and an FPGA real-time processing system is used to realize the weld quality monitoring in the industrial electron beam welding processes. The distribution law of backscattered electrons in space is simulated by Monte Carlo method, and the results show that the number of distribution in the 40°∼60° angle region is more, the backscattering coefficient increases with the increase of the incident angle of the electron beam, and the backscattering coefficient of the samples with large atomic numbers is relatively high. The field monitoring experiments show that the designed system exhibits good sensitivity to the characteristic morphology, and the imaging resolution reaches more than 200 μm, and the weld hole defects are clearly visible. A good linear correlation between the current change curve during scanning and the actual shape profile is shown, while the image resolution is better when the spot current is 1 mA.

Timing-accurate scheduling and allocation for parallel I/O operations in real-time systems

In industrial real-time systems, the I/O operations are often required to be both timing predictable, i.e., finish before the deadline to ensure safety, and timing accurate, i.e., start at or close to an ideal time instant for optimal I/O performance. However, for I/O-extensive systems, such strict timing requirements raise significant challenges for the scheduling of I/O operations, where execution conflicts widely exist if the I/O operations are scheduled at their ideal time instants. Existing methods mainly focus on one I/O device and apply simple heuristics to schedule I/O operations, which cannot effectively resolve execution conflicts, hence, undermining both timing predictability and accuracy. This paper proposes novel scheduling and allocation methods to maximize the timing accuracy while guaranteeing the predictability of the system. First, on one I/O device, a fine-grained schedule using Mixed Integer Linear Programming (MILP) is constructed that optimizes the timing accuracy of the I/O operations. Then, for systems containing multiple I/O devices of the same type, two novel allocations are proposed to realize parallel timing-accurate I/O control. The first utilizes MILP to further improve the timing accuracy of the system, whereas the second is a heuristic that provides competitive results with low overheads. Experimental results show the proposed methods outperform the state-of-the-art in terms of both timing predictability and accuracy by 37% and 25% on average (up to 5.56x and 33%), respectively.

Innovations in Time Related Expression Recognition Using LSTM Networks

The proposed architecture leverages the strengths of both Convolutional Neural Network (CNN) and Bidirectional Long Short-Term (BLSTM) to create a robust model for temporal expression recognition in clinical texts. The CNN component effectively captures morphological and orthographic features at the character level, which enriches the semantic understanding of complex medical terminologies that are often abbreviated or have unique suffixes and prefixes. The BLSTM component excels in capturing long-range dependencies in text, which is crucial for understanding the context in which temporal expressions occur. By integrating these models with a CRF layer, the system not only predicts discrete labels but also ensures that the sequence of predicted labels is coherent and contextually appropriate, addressing the limitations of models that predict labels independently. The integration of pre-trained biomedical word vectors provides significant contextual grounding tailored to the medical domain, enhancing the model's ability to discern and interpret the nuances of medical language. This is crucial in clinical contexts where accurate interpretation of temporal phrases can be critical for patient management and treatment timelines. Further, experiments conducted on the dataset validate the effectiveness of the proposed model, demonstrating a notable improvement over traditional methods that rely heavily on hand-crafted features and rule-based approaches. Future work could explore the adaptability of this model to other subdomains of the medical field and its efficacy in processing multilingual texts, potentially increasing its applicability in global healthcare settings, with further refinement of the neural architecture and optimization of training strategies potentially yielding even better performance and faster processing times essential for real-time clinical decision support systems.

ОСНОВНІ РЕЖИМИ РОБОТИ І ГРАФІЧНИЙ ІНТЕРФЕЙС КОРИСТУВАЧА КОМПЛЕКСУ ДЛЯ ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ МАГНІТНИХ ПОЛІВ І ДІАГНОСТУВАННЯ ЕЛЕКТРОЕНЕРГЕТИЧНОГО ОБЛАДНАННЯ

Hardware and software monitoring complex is designed to study the relationship between changes in the patterns of the magnetic field intensity distribution with power equipment failures. In experimental studies with predetermined techni-cal faults artificially introduced into the object the complex will provide useful and reliable results by registering changes in the magnetic field induction in the spatial, temporal and frequency domains. The choice and flexible adjust-ment of data collection tools by the researcher will ensure the use of the most appropriate method for measuring, con-verting and displaying information about the investigated faults. The article presents the main operating modes and graphical user interfaces of a personal computer and a mobile data acquisition system that jointly convert, store, ana-lyze and display measurement information received from various magnetic sensors. The generalized functional specifi-cation of the complex software, the design of the graphical user interface (GUI) as parts of the real-time operating sys-tem (RTOS) of the mobile data acquisition system (DAQ) and PC software will also be used in the development of prob-lem-oriented computer diagnostic systems for electric power equipment. Ref. 12, fig. 3.

Dynamic round robin with adaptive time quanta (DRRATQ): A proposed algorithm

The CPU scheduling technique influences the performance and efficiency of operating systems. Round-robin scheduling algorithm is ideal for time-shared systems, but it is not optimal for real-time operating systems since it yields more context switching, longer waiting time, and high turnaround time. The performance of the algorithm is predominantly influenced by the designated time quantum; however, determining a suitable time quantum is extremely challenging. This paper presents a CPU scheduling algorithm that provides a better tradeoff between waiting time, turnaround time, response time, and number of context switch by using hypothesis-based quanta generation approach. It combines the CPU burst requirements of actual processes with some noisy data and plots them against the presumed CPU quanta to get quanta densities so that a polynomial regression model can fit the data points with the highest adjusted R-squared. Then applying some complex inferential statistic, the required quanta is obtained. The scheduling is dynamic in nature because it generates the next CPU quanta in reference to the quanta that have been used in the previous cycle with remaining CPU burst requirements of the process, and it is also adaptive in nature because, at each cycle, it uses ‘d’ (5, 5, 4, 3, 2) degree of freedom to calculate the Jarque-Bera Statistics to accept/reject the hypothesis. The algorithm is implemented in ‘R’ and the performance has been evaluated on a sample size of five processes with some noisy data which outperforms the conventional RR and significantly reduces the performance parameters mentioned above. Implementing this algorithm to a time-sharing or distributed environment will undoubtedly improve system performance and will help to avoid issues like thrashing, incorporate aging, CPU affinity, and starvation. Since the proposed algorithm is work-conservative, therefore can be implemented in network packet switching, statistical multiplexing, and real-time systems.

Edge computing based real-time Nephrops (Nephrops norvegicus) catch estimation in demersal trawls using object detection models

In demersal trawl fisheries, the unavailability of the catch information until the end of the catching process is a drawback, leading to seabed impacts, bycatches and reducing the economic performance of the fisheries. The emergence of in-trawl cameras to observe catches in real-time can provide such information. This data needs to be processed in real-time to determine the catch compositions and rates, eventually improving sustainability and economic performance of the fisheries. In this study, a real-time underwater video processing system counting the Nephrops individuals entering the trawl has been developed using object detection and tracking methods on an edge device (NVIDIA Jetson AGX Orin). Seven state-of-the-art YOLO models were tested to discover the appropriate training settings and YOLO model. To achieve real-time processing and accurate counting simultaneously, four frame skipping ideas were evaluated. It has been shown that adaptive frame skipping approach, together with YOLOv8s model, can increase the processing speed up to 97.47 FPS while achieving correct count rate and F-score of 82.57% and 0.86, respectively. In conclusion, this system can improve the sustainability of the Nephrops directed trawl fishery by providing catch information in real-time.

Enhanced Compiler Technology for Software-based Hardware Fault Detection

Software-Implemented Hardware Fault Tolerance (SIHFT) is a modern approach for tackling random hardware faults of dependable systems employing solely software solutions. This work extends an automatic compiler-based SIHFT hardening tool called ASPIS, enhancing it with novel protection mechanisms and overhead-reduction techniques, also providing an extensive analysis of its compliance with the non-trivial workload of the open-source Real-Time Operating System FreeRTOS. A thorough experimental fault-injection campaign on an STM32 board shows how the system achieves remarkably high tolerance to single-event upsets and a comparison between the SIHFT mechanisms implemented summarises the trade-off between the overhead introduced and the detection capabilities of the various solutions.